CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 13,982	$ 53,717	$ 7,925	$ 42,992
Other comprehensive gain (loss):
Foreign currency translation gain (loss)	4,990	1,801	(4,830)	3,515
Income tax (expense) benefit on foreign currency translation gain (loss)	(1,267)	(457)	1,232	(892)
Foreign currency translation gain (loss), net of taxes	3,723	1,344	(3,598)	2,623
Gain (loss) on derivatives	364	(10,819)	(12,592)	(18,180)
Income tax (expense) benefit on gain (loss) on derivatives	(93)	2,744	3,212	4,611
Gain (loss) on derivatives, net of taxes	271	(8,075)	(9,380)	(13,569)
Total other comprehensive gain (loss)	3,994	(6,731)	(12,978)	(10,946)
Comprehensive income (loss)	17,976	46,986	(5,053)	32,046
Net loss attributable to the noncontrolling interest	24	117	18	156
Foreign currency translation (gain) loss, net of taxes attributable to the noncontrolling interest	(3)	(12)	95	(6)
Comprehensive loss attributable to the noncontrolling interest	21	105	113	150
Comprehensive income (loss) attributable to WW International, Inc.	$ 17,997	$ 47,091	$ (4,940)	$ 32,196